2: #include <../src/sys/classes/random/randomimpl.h>

  4: PetscErrorCode  PetscRandomSeed_Rand(PetscRandom r)
  5: {
  7:   srand(r->seed);
  8:   return(0);
  9: }

 11: #define RAND_WRAP ((PetscReal)((rand()/(double)((unsigned int)RAND_MAX+1))))
 12: PetscErrorCode  PetscRandomGetValue_Rand(PetscRandom r,PetscScalar *val)
 13: {
 15: #if defined(PETSC_USE_COMPLEX)
 16:   if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low) + (PetscImaginaryPart(r->width)*RAND_WRAP + PetscImaginaryPart(r->low)) * PETSC_i;
 17:   else *val = RAND_WRAP + RAND_WRAP*PETSC_i;
 18: #else
 19:   if (r->iset) *val = r->width * RAND_WRAP + r->low;
 20:   else         *val = RAND_WRAP;
 21: #endif
 22:   return(0);
 23: }

 25: PetscErrorCode  PetscRandomGetValueReal_Rand(PetscRandom r,PetscReal *val)
 26: {
 28: #if defined(PETSC_USE_COMPLEX)
 29:     if (r->iset) *val = PetscRealPart(r->width)*RAND_WRAP + PetscRealPart(r->low);
 30:     else         *val = RAND_WRAP;
 31: #else
 32:   if (r->iset) *val = r->width * RAND_WRAP + r->low;
 33:   else         *val = RAND_WRAP;
 34: #endif
 35:   return(0);
 36: }

 38: static struct _PetscRandomOps PetscRandomOps_Values = {
 39:   PetscRandomSeed_Rand,
 40:   PetscRandomGetValue_Rand,
 41:   PetscRandomGetValueReal_Rand,
 42:   NULL,
 43:   NULL,
 44:   NULL,
 45:   NULL
 46: };

 48: /*MC
 49:    PETSCRAND - access to the basic Unix random number generator

 51:    Options Database Keys:
 52: . -random_type <rand,rand48,sprng>

 54:   Level: beginner

 56: .seealso: PetscRandomCreate(), PetscRandomSetType(), PETSCRAND48, PETSCSPRNG
 57: M*/

 59: PETSC_EXTERN PetscErrorCode PetscRandomCreate_Rand(PetscRandom r)
 60: {

 64:   PetscMemcpy(r->ops,&PetscRandomOps_Values,sizeof(PetscRandomOps_Values));
 65:   PetscObjectChangeTypeName((PetscObject)r,PETSCRAND);
 66:   return(0);
 67: }